With the advent of portable radios for such uses such as public safety work, housings were developed which were more or less splash proof, since public safety officers are often exposed to adverse weather conditions in the course of their work.
When it became desirable to combine a data terminal with a portable two-way radio, it became obvious that many users of these would also be exposed to bad weather, and that combination units would also have to be at least splash proof. One-piece keyboards are known as in calculators, with a resilient cover and some type of tactile-response switches underneath designated areas of the cover. These, however, were not required to be splash proof since there was no expectation of outdoor use, and also the devices did not utilize a speaker/microphone.
Since, as in some of the intended applications of the present invention, the combined two-way data terminal/radio may be used in a train yard or ship yard, truck terminal or airport for freight management and routing, bad weather poses a serious problem to the dependability of the data terminal components. Also, any sound apertures must be well protected since they must prevent water access not only to the speaker and microphone but to the circuitry which, in such a compact device, must of necessity be closely adjacent. The interior components must, of course, be available for any necessary repairs.